Cognitive Neurophysiology Laboratory

CNL Wiki

Docs: Running Video Clips

Updated on October 6, 2023

Video Clips (11/2020 update)

Equipment needed:

  • Experimental laptop
  • DAQ
  • Microphone
  1. Prepare patient-specific clips and place them: /Users/NattyBoo/MYLOCALWORKINGCOPY/PARADIGMS/VIDEOCLIPS/ClipsUsed/Pt #
  2. Create input/output paths similar to: /Users/NattyBoo/MYLOCALWORKINGCOPY/PARADIGMS/VIDEOCLIPS/ filepaths_530.mat
  3. Open Matlab_R2018b and make sure that you are on: /Users/NattyBoo/MYLOCALWORKINGCOPY/PARADIGMS/VIDEOCLIPS/
  4. Load filepaths_#.mat by double clicking on it on the left panel
  5. Double check your paths by typing the following separately: loadFrom and writeTo
  6. Run the task via the following command (from this level: /Users/NattyBoo/MYLOCALWORKINGCOPY/PARADIGMS/VIDEOCLIPS/):


During the first 6 sets, the patient should be viewing the videos without any other task. This is followed by the distracter phase (odd/even), then free recalled, then cued recall. Please see below for further details.

Phase 1: Clip viewing

There are 10 clips (~15s long each) that are chosen based on the screening results, that will be presented in randomized order (with 2s delay in between clips).

This round will be repeated 6-8 times (in each round, order of clips are randomized differently). Ideally we will have a 15s delay between rounds (not sure if Emily has implemented this yet).

Phase 2: distractor

Participants will do the odd even task for ~ 30 seconds

Phase 3: free recall

Before the experiment, on a sheet of paper please write down the name of the 10 clips.

Ask the participant: please describe each of the clips you saw with as much detail as possible.

put a check mark next to the clips they describe

Phase 4: cued recall

If, according to your list, there is a clip that they are missing, just ask them: “how about the clip with X (person or animal) in it” and put a check mark after they finish describing that.

During the entire experiment, please make sure you’re recording the audio.

Running Video Clips


  1. Download video clips from shows the patient enjoys
  2. Choose ~20 video clips, trim them to ~10 seconds each.
  3. Write down one question you can ask from each clip (essentially, a prompt to recall a specific detail from the clip; the question must be specific enough that it should recall a specific clip even if the patient hasn’t just seen the clip. For example “What kind of sandwich did Shaggy ask for?” not “How did Shaggy feel?”
  4. Make sure that CNLttl, _SetMyGamepad, VMfdbk_SetMyKeyboard and AskQuestionRecordYNanswer are in your path. Get these from PIPELINE_vc/CODE/Scratch (or ask Natalia if they’ve moved).


Syntax: playVideoClips(loadFromFolder,writeToFolder,nIterations,debugMode,askEmotionQuestions,includeDistractorBeforeRecall,postRoundDelay)

loadFromFolder should be the location where the 20 video clips are stored.

writeToFolder should be where you want results saved

nIterations is the number of times the clips will be viewed before recall and/or emotion questions

debugMode should be 0 if running the tast for real

askEmotionQuestions should be 1 if you want the task to ask questions about how scary, funny, etc. each clip was. We originally wrote this for a patient with good amygdala responses, so we wanted to get emotional reactions.

includeDistractorBeforeRecall should be 1 if you want to put an odd/even task in between viewing the clips and asking for recall.

postRoundDelay (default 10 seconds)

  • Connect a game pad, but you can keep it; You will use it to advance through questions after the patient responds.
  • Make sure microphone is on and working.
  • The video clips will play through nIterations times uninterrupted.
  • If includeDistractorBeforeRecall, it will switch to the odd/even distractor task. Patient will use arrow keys to indicate odd or even.
  • Then will pause and a screen will say “Please tell us about the movie clips you remember.” Allow the patient to recall as much as possible from the clips without any prompting. Then, ask the questions you wrote down about each clip (in a random order).
  • Press a button on the game pad to continue.
  • If askEmotionQuestions is true, the clips will play through again, one at a time. After each clip, there will be a series of “On a scale of 1-10,…” questions. Record patient’s answers and press a button on the game pad to continue after each answer.